Pseudo-traditional harmonic functions of octatonic scale degrees

Degree number	Function	Regular triad
I	Tonic	I-III-VI
II	Supertonic	II-IV-VII
III	Mediant	III-V-VIII
IV	Subdominant	IV-VI-I
V	Antitonic	V-VII-II
VI	Dominant	VI-VIII-III
VII	Submediant	VII-I-IV
VIII	Leading tone Subtonic	VIII-II-V

Due to regular triads not being able to simply skip every other note, the regular VIII triad uniquely contains both degrees which are dissonant to the tonic.